Nicholas J. Gutierrez: Acoustic mating signals play an important role in sexual selection both for identifying species and assessing potential mates. These same signals can vary due to environment or genetics, but how might they vary across a group of related organisms? Using three sister/related species of Gryllus crickets (Gryllus lineaticeps, G. personatus, and G. sp15/‘G. staccato’), I compared male calling song (a sexually selected signal) across all three species in response to environmental (diet) and genetic (family) sources of variation. While environmental factors did have an effect on some body measurements, it did not have an effect on song traits in any of the three species. However, genetic factors did have an effect on song traits vital to identifying and choosing a mate in a consistent pattern of response across all three species, a comparative first for crickets with the potential for other groups of related organisms.